Charging apparatus for the furnace

ABSTRACT

The invention is concerned with an apparatus for charging raw materials or ore rocks into a furnace, and uses four bells namely a large bell, a middle bell, a small bell and a rotating hopper bell serving as the charging apparatus for the furnace, and these bells are formed so as to provide sealing and charging or distributing functions and each of them is suitably operated to smoothly charge raw materials as well as to seal the top of the furnace to thereby fully maintain the pressure at the top of the furnace in order to provide excellant furnace operation.

United States Patent Sugawara et al.

[ CHARGING APPARATUS FOR THE FURNACE [72] Inventors: Tsunenori Sugawara;Te'tii Shibuya;

Satoru Miyakado; Jiro Mase, all of Fukuyama, Japan [73] Assignee: NipponKokan Kabushiki Kaisha,

Tokyo, Japan [22] Filed: May 8, 1970 [21] Appl. No.: 35,775

[30] Foreign Application Priority Data l/l967 Mohr, Jr.. ..266/27 51Oct. 3, 1972 Melcher et al ..2l4/36 Dougherty et al ..2l4/36 PrimaryExaminer-Gerald M. Forlenza Assistant Examinerf-John MannixAttorney-Linton 8L Linton [57] ABSTRACT The invention is concerned withan apparatus for charging raw materials or ore rocks into a furnace, anduses four bells namely a large bell, a middle bell, a

' small bell and a rotating hopper bell serving as the chargingapparatus for the furnace, and these bells are formed so as to providesealing and charging or distributing functions and each of them issuitably operated to smoothly charge raw materials as well as to sealthe top of the furnace to thereby fully maintain the pressure at the topof the furnace in order to provide excellant furnace operation.

14 Claims, 4 Drawing Figures PATENTEIJnm 3 m2 SHEET 1 [IF 3 INVENTOIZSsueAwARp,

BU m YAKRDO AND HSE SUIYEIVORI EIJI SH TORU IRO M T TST PATENTED um 31922 saw 3 or 3 SPTORU IYDKADDAND J JRQ MASE H ORNEYS CHARGING APPARATUSFOR THE FURNACE Most of the conventional charging apparatus is of the socalled McKee Type, and this McKee charging apparatus is a two bellsystem provided with a large bell at the lower part thereof as well assmall bells at the upper part one over the other through which thematerials are charged into the furnace. Recently the furnace has becomelarge scaled, and high top pressure operation has been adopted, and thefurnace cannot follow the operating circumstances by means of the McKeeapparatus because of its high development. Thereupon,

furnaces have been devised, e.g., with a double small bell which is usedto provide uniform chargings of material, or as disclosed in theJapanese Patent Publication No. 13,121/66 the rotating hopper whichcharges the raw materials on the small bell is eliminated, and therotating chute is built in the bell hopper which is a fixed closedvessel and thisrotating chute is rotated by means of an outside drivingdevice, also a gas seal valve is arranged between the opening throughwhich the material descends and the raw material receiving hopper sothat the gases are perfectly sealed for the simple apparatus, and thusthose furnaces maintain the pressure at the top of the furnace as wellas the gas pressure in the furnace in those ways to provide the desiredhigh top pressure operation. However in those prior methods the furnacehas been so large such as 2,000 to 3,000m or more in the furnace volume,and 7,000mm or more in the large bell diameter, and ZKg/Cm or more inthehigh top operation, and it is difficult to provide satisfying resultson account of gas tightness, segregations of the charged materials orabrasions of members in the top charging apparatus. According to theprior structure as above mentioned, in the case of a large scaledfurnace up to 3,000m in the volume, the charging raw material is widelyspread due to the large size of the lower bell not to avoid segregationsin its dispersion, especially remarkable in the case of small particlematerials such as in lime, manganese or other. Besides the sealing valveis arranged for this rotating chute at the charging opening, but as thissealing valve portion stays and adheres the dusts, its sealing effectcannot be expected. Still further such a chute is fairly worn in thechute system since the raw material is supplied in contact to the chuteand has such disadvantages as not avoiding the crushing of variousmaterials. Attention must be especially paid when a leak is createdanywhere in the sealing part as the gases are blown up from such a partowing to the high top pressure exceeding 2Kg/Cm and since thisblowing-up gas bear dusts, said seal leak is quite extended in a shortperiod so that accidents or abrasion are brought about. In said largescaled furnace, the amount of gas at the furnace top well exceeds'5,000Nm-"/min, and although such a pressure as 2Kg/Cm? may be low inview of other industrial processesthe leaking speed is up to thesupersonic velocity, and as said little leakage instantly can cause alarge accident, little faults are very possible because of the largescale.

The present invention has succeeded in providing an apparatus forcharging raw materials into the furnace to really meet the abovementioned large scaled furnace operation through detailed examinationsand investigations in view of such actual circumstances.

The basic object of the invention is to permit the smooth charging ofthe raw materials while maintaining a suitable pressure at the top ofthe large furnace. It is not always easy to charge the raw materialssmoothly while well maintaining the pressure i.e., in order to maintainthe pressure the top of the furnace must be sealed. As above described,it has been the practice to provide the bells in steps at the chargingopen, and at the time of charging the raw materials from one of thebells, the rests of them are closed to provide a seal, and suchoperations are alternately repeated or the systems are used which adoptthe special rotating hoppers. However, even according to those systems,desireable results are not obtained in said large scaled and highpressured furnaces. In the above stated high top pressure operation, thefurnace gas inavoidably blows out at the opening and closing of each ofthe bells, besides considerable amounts of powder dusts (e.g., more than20g/Nm floats in this furnace gas so that the sealing parts between thebells and hoppers is always worn by said leaking gases to increase thegas leakage which followed by abrasion, prevents maintaining thepressure at the top of the furnace. The raw materials to be suppliedfloat in contact to the bell or hopper side at supplying and falling,and at this point those members are worn. Moreover, since those membersare confronted with a high temperature, the sealing effect at therotating means is not increased.

The invention uses a four bell system so as to prevent those problems,and maintains the pressure at the top of the furnace as well as securingthe raw material charging, and further each of the bells takes partialcharge of distributing the raw materials and work as a seal. in thismanner, each of the bells and each of the hoppersrespectively providefor supplying, distributing or sealings, i.e., the bells and the hoppersfor the raw materials accomplish usefully and suitably those objectivesand the bells and hoppers for sealing also function withoutinterferences thereby exactly provide for the maintaining of thepressure and charging and distributing the raw materials for a longperiod.

Another object lies in obtaining a charging apparatus for uniform aswell as efficient operation. Therefore the invention uses a rotatinghopper bell for the uppermost bell or the charging means in order toprovide for the uniform distribution of the raw materials from thebeginning of the charge at the top of the furnace. Such a hopper bell isdesigned only for charging to thereby cancel the technical difficultiesof rotating this part as well as serving the seal as in the prior art toaccomplish the destined charging with a simple composition. Even if theraw materials fall into between the hopper and the bell, the rotatinghopper bell only for charging can accomplish its required work so thatthe raw materials are fed to said rotating hopper through a continuousbelt conveyor, and special means are no longer required such as adoptthe intermittent skip to singly supply the raw materials thereonto orintermittently drive the belt conveyer to prevent the raw materials fromfalling between the hopper and the bell. Besides it is possible tocontinuously and efficiently charge the raw materials with the beltconveyor thus more improve the large scaled furnace operation.

Notwithstanding the multi-bell step composition, the invention providesa charging apparatus of a comparatively lower figure. The four bells arearranged at the top of the furnace, which will avoid the larger andhigher figure. The higher furnace requires more structural materials andcosts for the furnace construction, being further followed by the largeconveying equipment, driving means or other bringing the largeness allover the furnace. However, in the invention the bell having only saidscaling function it is not essential to form a hopper which stores theraw material but possible to remove this hopper at least in one part.Therefore in spite of the four bell system the height of the top furnacedoes not increase so much, and the construction cost is economical.

Other excellent characteristics or working effects will be apparent withreference to the explanations on the disclosed embodiments.

The attaching drawings show the invention embodiments, wherein:

FIG. 1 is a cross-sectional view showing the whole charging apparatus;

FIG. 2 is an enlarged cross-sectional view of the bell parts;

FIG. 2A is a further enlarged cross-sectional view of a detail, and

FIG. 3 is an enlarged cross-sectional view of the rotating hopper parts;

Explanations will now be given concerning the embodiments of theinvention with reference to the attaching drawings: FIG. 1 shows one ofthe useful embodiments that is, the invention adopts at the top part ofthe furnace 10, the four bell system of the large bell 1, middle bell 2,small bell 3 and rotating hopper bell 4. Among them the large bell 1 andthe rotating hopper bell 4 are formed for charging the raw materials,and the middle bell 2 and the small bell 3 between them are devised toserve for gas sealing. In other words, the invention is to separatelyperform the functions of the large bell and small bell in the above saidMcKee system, i.e., the charging function as well as the gas sealingfunction by means of independent bells, thereby eliminating the faultsdue to one bell which operates the charging and sealing functions as inthe conventional apparatus, and securing a perfect charging and sealingoperation. To further explain this as follows, the furnace isprovided'at its open top with a large bell hopper 1a to which a centralrod 11 is connected, i.e., said large bell hopper 1 is provided foroblique adjustment with a ball seat 15 at the end of the central rod 11which is vertically moved by a large bell lever 7 arranged on a top deck16 at the uppermost rotating hopper 5. Said large bell hopper 1a isfurnished on its top with a ring wall 10 with a middle bell hopper 2a towhich the middle bell 2 is arranged, and this middle bell 2 is openedand closed by a middle bell lever 6 opposite to said large belloperating lever 7. The upper end of the middle bell adjusting pipe 12concentric with said central rod 11, is connected to the lower ends ofrods 6b, 6b depending from an arm 6a of the middle bell lever 6, and themiddle bell 2 is attached on the lower portion of said middle belladjusting pipe 12. The middle bell hopper 2a is equipped with a ring onits upper portion supporting a small bell hopper 3a therein for thesmall bell 3, and this small bell 3 is vertically operated by itsattachment to pipe 13 operated by a driving unit 8 as a trunnioncylinder, on a middle deck 17 positioned below the lower part of the topdeck 16 having the operating levers 6, 7. The small bell hopper 3a isprovided at its upper end with said rotating hopper 5, at the lower openend of which is arranged the rotating hopper bell 4. Said rotatinghopper 5 is supported on the deck 20 together with the driving gear 18,and this rotating hopper bell 4 is vertically moved through the rod 14by means of another gear 9 which is crossed with said driving unit 8 onthe middle deck 17. In this connection, a chute 50 as shown in FIG. 3faces said rotating hopper 5 into which the raw materials are supplied.A sounding means 19 is provided on the said lower deck 20.

There are respectively provided raw material chambers 101, 102 betweenthe large bell 1 and middle bell 2 and between the middle bell 2 andsmall bell 3 respectively but such chambers are not provided betweensaid small bell 3 and the rotating hopper bell 4, and they are providednear each other. The part between the small bell hopper 3a and therotating hopper 5 is relieved for the atmospheric air as the cases maybe, and therefore the top of the little bell 3 is made readily for theatmospheric pressure. 21 is a waste gas duct.

FIG. 2 shows the enlarged bell parts. Said large bell 1 has on its upperside a protective shroud 1d to prevent abrasions owing to variousfalling materials. The lower periphery of this large bell 1 is oppositeto a flaring section 1b at the lower part of the large bell hopper 1a inorder to seal the gases. However this large bell 1 and flaring section1b are designed mainly for distributing the raw materials and theseparts are adjacent to the high temperatured furnace so that they adoptthe cast metals such as the heat resisting steel of enough thickness aswell as abrasion resistibility.

The middle bell 2 on the large bell 1 is designed for the sealingfunction, and accordingly the middle bell hopper 2a has fixed on itslower end a ring shaped flaring body 22 of C shape in cross section, andthe flaring body 22 is fixed at its lower end with a ring shaped packingmaterial 23 of heat resisting rubber with fitting plate 26. This ringshaped packing material 23 is appropriately expanded out from the innerslanting side of said flaring body 22 and accordingly when the middlebell 2 is raised up as shown, the sealing relationship is formedautomatically between this packing material 23 and the lower peripheryof the middle bell 2. The protecting pipe 24 is arranged with a trumpetshape to cover the upper end of the middle bell 2 and its shelteringring 25 covers the middle bell adjusting pipe 12 within the necessaryextent at this upper part of this sheltering pipe 24 so as to avoiddamages thereto by various falling materials.

The small bell 3 is also devised for the sealing function, and the smallbell hopper 3a is at its lower end fixed with a flaring body 32 of Cshape in cross section similar to body 22 of the middle bell, and thepacking material 33 is fixed with a fitting plate 36 at the lower end ofthe flaring body 32. However since this small bell 3 is, apparantly fromthe shown state, always covered with the rotating hopper bell 4, itsupper part is only furnished with a simple cover 34 and does not requirea sheltering pipe or ring as in the middle bell 2.

The rotating hopper 5 for the rotating hopper bell 4 is supported on thelower deck 20, and further as shown in FIG. 2 a space 38 is provided inrelation to the hopper member 37 on the small bell hopper 3a to contactthe atmospheric air. Said lower deck 20 is provided with a driving motor18, and a gear 46 driven by this motor 18 engages with a ring shapedgear 47 which is provided outside of supports the rotating hopper 5 andwhich is supported on a roller 48 mounted on the lower deck 20, and therotating hopper 5 is driven by driving said motor 18. In the middlebell, the protecting pipe 14 and ring 42 are provided in steps on theupper rotating hopper bell 4.

The raw materials are supplied into said rotating hopper 5 by means of achute 50 fixed on the middle deck 17, into which the raw materials arecontinuously fed through the belt conveyer 51, and the lower part of thechute 50 has open end branches extending to both sides of the operatingpipe 14, see FIG. 1. These branched openings 54 are respectivelyequipped with dampers 55 to be temporarily closed. A suitable protectingmember 52 is furnished on the inner side of this chute 50 to prevent itfrom shocks caused by charging of the various materials. The large bell1 among the bells is the largest, and in order to suspend it said ballseat 15 is adopted to provide an appropriate contact of bell 1 inrelation to the flaring body lb.

To explain the charging operation according to the present system, whenthe rotating hopper 5 is moving the predetermined raw materials aresupplied into the rotating hopper 5, and when the inner chamber 102 onthe middle bell 2is made in the condition of the atmospheric pressure,the small bell 3 is opened, and subsequently when the inner chamber 102on the middle bell 2 is made in the condition of the atmosphericpressure the rotating hopper bell 4 is opened, the raw materials in therotating hopper 5 is laid on the middle bell 2, and in this manner afterthe raw materials are moved to the middle bell 2, the small bell 3 isfirst closed and the rotating hopper bell 4 is closed. In this case thesmall bell 3 and the rotating hopper bell 4 may be simultaneously openedand closed. As above mentioned when the raw materials are moved onto themiddle hell 3, the small bell 3 and the rotating hopper bell 4 areclosed, then said chamber 102 is made in the condition of the sameatmospheric pressure as the chamber 101 on the large bell l and themiddle bell 2 is opened whereby the raw materials fall on the large belll. Apparently after the middle bell 2 is closed, the large bell l isopened so that the raw materials are charged or distributed into thefurnace, and in the meanwhile the next supply of raw materials arestored on the damper 55 in the hopper 5. Thus the above mentionoperations are repeated in succession to charge the raw materials intothe furnace.

Furthermore, as the raw materials are supplied from the rotating hopper5 to the furnace by means of the bell system, the self-cleaning effectsby the falling raw materials are exactly provided and the raw materialsor powder dusts do not adhere to the sealing part at all and thereforegas blowing is unnecessary for cleansing the powder dusts. The gastightness of the large bell is not absolute because of its largediameter in view of the heat resistibility or abrasion resistibility,but the middle bell 2 and the small bell 3 both serve for sealing thegas in two steps to obtain the perfect gas sealing and exactly maintainthe high top pressure. Especially, since the sealing part of the smallbell 3 is not exposed at any time to the top furnace gas of hightemperature and high pressure it is possible to obtain a good sealingfunction in which material such as rubber is used. The rotating hopperand the rotating hopper bell can be operated in the atmospheric pressurewithout trouble concerning the seal on such rotating parts as well aswear of the member contacting the furnace gases of high temperature andhigh pressure which bear powder dusts, but with easy maintenance andobservations. In spite of the four bell system a high rotating chute isnot adopted, and the rotating hopper bell and the little bell arepositioned near each other to reduce the height. Especially the rotatinghopper and the small bell are re lieved under the atmospheric pressurecondition to greatly reduce the capacity exposed in the furnace gasatmospheric of high temperature and high pressure. The operation is'easy and smooth with a large amount and high pressure system.

We claim:

1. A charging method for a furnace, consisting in arranging at the topof the furnace, in the order from the furnace side, hoppers, a largebell, middle bell, small bell and rotating hopper bell positioned inrelation to the respective hoppers therefor, uniformly distributing theraw materials to lay onto the small bell, feeding from this small bellto the large bell through the middle bell, and thereafter opening saidlarge bell to charge the raw materials into the furnace.

2. A charging method for a furnace, as described in claim 1, includingrotating said rotating hopper continuously, feeding the raw materials bymeans of a belt conveyer, opening the small bell and subsequentlyopening the rotating hopper bell, supplying the uniformly distributedraw materials onto the middle bell, after closing the rotating hopperbell and the small bell, opening the middle bell to feed the rawmaterials onto the large bell, and in this manner opening the large bellto charge the raw materials into the furnace under the condition that atleast the middle bell is closed, preferably the middle bell as well asthe small bell are closed.

3. A charging method for a furnace, as described in claim 1, includingopening the closing of the rotating hopper bell under atmosphericpressure.

4. A charging method for a furnace, as described in claim 1, includingadopting the seal means which utilize packing materials on therespective hoppers for the middle bell and the small bell, and chargingthe raw materials while maintaining enough air-tightness in any of thesebell hoppers.

5: A charging method for a furnace, as described in claim 1 includingunder such a condition that one of the middle bell or small bell isclosed, opening the remainder of said bells in order to supply the rawmaterials when either said middle bell or small bell is closed.

6. A charging method for a furnace, as described in claim 1, includingclosing at least one of said middle bell or small bell and at least oneof said large bell or rotating hopper bell, and opening the other bells.

7. A charging apparatus for a furnace comprising fixed hoppers, a largebell, middle size bell, small bell, said bells being mounted with saidmiddle size bell above said large bell and said small bell above saidmiddle size bell and said large bell above the top of a furnace, each ofsaid hoppers being positioned with a different one of said bells capableof opening and closing its respective hopper, a rotatable hopper bellmounted above said small bell, means for vertically moving each of saidbells independently relative to its hopper and a driven rotatable hoppermounted over said upper rotatable hopper bell.

8. A charging apparatus as described in claim 7, wherein the lowermostlarge bell and the uppermost rotating hopper bell as well as the hopperstherefor are designed chiefly for charging the raw materials, and themiddle bell and the small bell as well as the hoppers therefor aredesigned for perfect sealing function with packing materials.

9. A charging apparatus as described in claim 7, wherein each of saidhoppers relative to the middle bell and the small bell is respectivelyprovided at its lower portion with a flaring part of C shape in crosssection, and ring shaped packing material is appropriately expanded outfrom the inner slant side of said flaring body.

10. A charging apparatus as described in claim 9, wherein said ringshaped packing materials is fixed on the lower slant inside of theflaring part with a fitting plate which is equipped under said packingmaterial.

1 l. A charging apparatus as described in claim 7, including a spacebetween the upper portion of said small hopper and said rotating hopperor the rotating hopper bell to relieve the inner part of the small bellhopper to the atmospheric pressure. 7

12. A charging apparatus as described in claim 7 wherein the rotatinghopper and the small bell or the small bell hopper are arranged in closerelation, and form a raw material chamber on the small bell or smallbell hopper.

13. A charging apparatus as described in claim 7 including a chutearranged at said rotating hopper, and a belt conveyer for feeding rawmaterials to said chute.

14. A charging apparatus as described in claim 7, including a tubed rodconnected to said middle bell, a rod within said first rod, connected tosaid large bell, a tubed rod connected to said small bell andconcentrically arranged outside of the tubed rod for said middle bell, atubed rod connected to said rotating hopper bell concentrically arrangedoutside of the tubed rod for said small bell, and means for verticallymoving said rods.

1. A charging method for a furnace, consisting in arranging at the topof the furnace, in the order from the furnace side, hoppers, a largebell, middle bell, small bell and rotating hopper bell positioned inrelation to the respective hoppers therefor, uniformly distributing theraw materials to lay onto the small bell, feeding from this small bellto the large bell through the middle bell, and thereaftEr opening saidlarge bell to charge the raw materials into the furnace.
 2. A chargingmethod for a furnace, as described in claim 1, including rotating saidrotating hopper continuously, feeding the raw materials by means of abelt conveyer, opening the small bell and subsequently opening therotating hopper bell, supplying the uniformly distributed raw materialsonto the middle bell, after closing the rotating hopper bell and thesmall bell, opening the middle bell to feed the raw materials onto thelarge bell, and in this manner opening the large bell to charge the rawmaterials into the furnace under the condition that at least the middlebell is closed, preferably the middle bell as well as the small bell areclosed.
 3. A charging method for a furnace, as described in claim 1,including opening the closing of the rotating hopper bell underatmospheric pressure.
 4. A charging method for a furnace, as describedin claim 1, including adopting the seal means which utilize packingmaterials on the respective hoppers for the middle bell and the smallbell, and charging the raw materials while maintaining enoughair-tightness in any of these bell hoppers.
 5. A charging method for afurnace, as described in claim 1 including under such a condition thatone of the middle bell or small bell is closed, opening the remainder ofsaid bells in order to supply the raw materials when either said middlebell or small bell is closed.
 6. A charging method for a furnace, asdescribed in claim 1, including closing at least one of said middle bellor small bell and at least one of said large bell or rotating hopperbell, and opening the other bells.
 7. A charging apparatus for a furnacecomprising fixed hoppers, a large bell, middle size bell, small bell,said bells being mounted with said middle size bell above said largebell and said small bell above said middle size bell and said large bellabove the top of a furnace, each of said hoppers being positioned with adifferent one of said bells capable of opening and closing itsrespective hopper, a rotatable hopper bell mounted above said smallbell, means for vertically moving each of said bells independentlyrelative to its hopper and a driven rotatable hopper mounted over saidupper rotatable hopper bell.
 8. A charging apparatus as described inclaim 7, wherein the lowermost large bell and the uppermost rotatinghopper bell as well as the hoppers therefor are designed chiefly forcharging the raw materials, and the middle bell and the small bell aswell as the hoppers therefor are designed for perfect sealing functionwith packing materials.
 9. A charging apparatus as described in claim 7,wherein each of said hoppers relative to the middle bell and the smallbell is respectively provided at its lower portion with a flaring partof C shape in cross section, and ring shaped packing material isappropriately expanded out from the inner slant side of said flaringbody.
 10. A charging apparatus as described in claim 9, wherein saidring shaped packing materials is fixed on the lower slant inside of theflaring part with a fitting plate which is equipped under said packingmaterial.
 11. A charging apparatus as described in claim 7, including aspace between the upper portion of said small hopper and said rotatinghopper or the rotating hopper bell to relieve the inner part of thesmall bell hopper to the atmospheric pressure.
 12. A charging apparatusas described in claim 7 wherein the rotating hopper and the small bellor the small bell hopper are arranged in close relation, and form a rawmaterial chamber on the small bell or small bell hopper.
 13. A chargingapparatus as described in claim 7 including a chute arranged at saidrotating hopper, and a belt conveyer for feeding raw materials to saidchute.
 14. A charging apparatus as described in claim 7, including atubed rod connected to said middle bell, a rod within said first rod,connected to said large bell, a tubed rod connected to said small belLand concentrically arranged outside of the tubed rod for said middlebell, a tubed rod connected to said rotating hopper bell concentricallyarranged outside of the tubed rod for said small bell, and means forvertically moving said rods.